The table top chain is used for carrying and transporting articles on a top plate. In the table top chain, rails for supporting the chain are disposed along the reciprocation track of the chain, and the rails are secured to a conveyor frame, for example, by means of small machine screws.
However, during the running of the table top chain, abraded powder is formed on the sliding surface between the support rail and the top plate. Particularly, in a table top chain used without lubrication, since the support rail and the top plate are often made of a resin, an abraded powder is formed most markedly at the initial stage of the operation.
In conventional support rails, since the upper surface is flat, there is no substantial room for allowing the abraded powder to escape. The abraded powder is discharged, for example, laterally from the sliding surface and accumulates on the support rails to markedly degrade the outer looks of the conveyor. Also, abraded powder is deposited onto articles, causing a problem in view of quality, in a case where the table top chain is used for the transportation of foodstuffs or chemicals.
Further, when the table top chain is used in a wet situation, liquids intervening on the sliding surface make the support rail and the top plate be in close contact with each other. This increases the resistance to running to necessitate a large power for traction of the table top chain.
Further, if the support rail and the top plate are made of metal, lubrication for the sliding surface is necessary. However, if a lubricant is supplied in a somewhat excessive amount with a view of preventing lubricant from exhaustion, the lubricant leaks out of the sliding surface to cause problems, like that in the abraded powder, of degrading the outer looks and deposition of the lubricant to articles.